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1. Cause

To illustrate the cause of the warming, here’s a graph from the last 6000 years showing temperature and carbon-dioxide levels.

It shows that carbon-dioxide levels were pretty flat and that temperature levels were slightly declining. When the industrial age began we started pumping massive amounts of carbon-dioxide into the air.

The extra CO2 then behaved like an extra blanket causing less heat to be radiated out into space.
In turn the extra heat caused temperature levels to rise.

Except for the extra carbon-dioxide in the air there are no major natural phenomena known that could have caused this. Natural cycles like the Milankovitch cycle have a very slow effect on the Earths climate. As the sun’s energy has been declining since 1960 it should be cooling.
Volcanoes can’t be the culprit either as we humans emit 100 times more CO2.

Natural phenomena can have short term implications on the Earths temperature. Sulfur emitted from volcanoes have a short term cooling effect.
A big 93% of the warming goes into the Earth’s oceans compared to a merely 2,3% that warms our thin atmosphere.

Oceans-cycles like El Nino and La Nina’s therefore have a big effect on the planets temperature. Throw in all the particles and aerosols we emit, include the 11 year sunspot cycle and the picture gets quite messy. The result in the warming is a combination of a jagged saw and a staircase.

This is the main reason why climate scientists always focus on the long term warming trend rather than the short term one.

2. Effects

As a result glaciers all over the world have been retreating, there’s less and less Arctic sea ice and Greenland is close to irreversible melting.

Muir Glacier, Alaska in 1941 and 2004

As the oceans warm, like anything that warms, it expands causing most of the sea level rise.

Historical sea level rise

The steady acceleration of sea level rise continues today and is a very big sign that warming hasn’t stopped at all, to the contrary!

Most disturbing is the triggering of so called feedback loops. An obvious one is in the Arctic.
When Arctic sea ice shrinks, less and less sunlight gets reflected back into space as oceans absorb far more sunlight than sea ice does. The extra warmth then causes more sea ice to melt so the oceans absorb even more sunlight and a feedback loop is born.

It’s also the case that most of the warming graphs don’t include the warming in the Arctic except for the ones that include satellite data. The graph made by Cowtan and Way shows an accelerated warming when the Arctic is included!

Another feedback loop is hiding in the permafrost. When the permafrost thaws, it releases more and more greenhouse gasses. These gasses then cause more and more warming and … you get the picture.

Antarctic land ice has begun to melt well ahead of scientists predictions, oceans are acidifying, there’s more droughts, more forest fires, species migrations and extinctions and lots more. But I’m afraid I have to cut it short here. I hope you’ll understand.

3. Solution

So how can we solve this? Well, it might surprise you, but the solutions are already here. What is mostly lacking is political will power to implement them.

As you might have heard we need to limit the warming to 2 degrees Celsius (3,6ºF) compared to pre-industrial levels. This is a popular view among politicians. Scientists however warn us that we need to limit the warming to just 1.5ºC (2.7ºF). But as the super powers have been dragging their feet for so long this now seems very hard to do. In fact we’re very much in danger of not even achieving the 2ºC limit. Current business as usual scenarios take us well beyond that (IPCC 3.2-5.4ºC pathway).

Not achieving the 2ºC limit will lead to certain disaster and runaway global warming could set in. The time we have to prevent this is running out quickly. A strong and ambitious climate agreement at the next COP 21 in Paris 2015 is very much needed.

The common idea is to roughly half emissions by 2030 and to have little emissions left by 2050. For some this might look like an impossible task, but for the ones that have already been leading a green life for some time now, this certainly looks achievable!

I’m not going to tell you to change your light bulbs or to separate your garbage. The solutions go well beyond that. Left and right need to team up as if we we’re putting the first man on the moon. Eliminate fossil fuel subsidies, put a price on carbon and if needed tax bad countries. Local economies will be stimulated. The transition will cost jobs, but will create many new ones as well. If jobs are the criteria for action, I can tell you this much.